Method of casting ingots



v 3 036 l.. B. I lNvDElx/IUTH` 2,37

June 50, 1943 INVENTo. LEWIS 5.-L/NDEM H.

' ATTRNEK 7 HWMIE/ April 3, 194,5.

Patented llApr. 3, 1945 s `lea'rvrsilv'lA OFFICE Marnon or @asumo moorsp Lewis B. Lindemlith, Port lll. assigner, by meoue ausente, to Steellnzot stom.

Production, lnog, a corporation ol ware Application .le dll, luth, Se loi No. 492,953

' (oi. et-evm My invention relates to ingot molds and a method ofcasting ingots of ferrous metals, such as steel or other metals.

lngots of steel or other ferrous metals are generally cast in iron orsteel molds, which may have either an integral or removable bottom. Ineither case the molten metal upon pouring or teeming into the empty moldstrikes the bottom ol the mold with considerable force and being at themelting temperature tends to wear away or erode that portion of thebottom ofthe mold on which it impinges.- IThis has a tendency to formcavities in the mold, or the bottom of the mold.

and after cavities havethus been formed or eroded in the mold the castmetal may solidify therein and may partly weld thereto and thus make itdlfiicult to remove the cooled ingot from the mold.

My present-inventionprovides an ingot mold and a method of casting theingot in such a way w1 as to prevent or minimize this erosion of thebottom surface of the mold and to avoid the tendency oi ingots to stickto the mold.

In my invention I protect the bottom surface of the mold cavity with alayer or dim of lead mi in such a manner that when the molten steel, orother ferrous metal, is poured or teemed into the `mold it does notstrike the metal oi the mold directly but instead lmpinges on the lead.

inasmuch as the lead melts at a much lower temperature than steel andhas a greater density or specific gravity and does not alloywiththesteelit`not only protects the bottom of the l vmold from erosion butwhen the mold is lled r as` a liquid layer or llm between the bottom ofthe mold and the insot and does not in any way interfere with the insot.

composition oi' the inasmuch as ne lesa is man 'itis displaced onlytemporarily by the molten `steel as the latter t0 e oi the pouredrmetalmay be expended in displac- .is poured into the mold and though it maybe ,displaced temporarilybythe stream of molten metal it inmediatelysinks a the bottom of the mold as the lling ol the mold proceeds and as.the lower part-oi the metal becomes quiescent.

There is, therefore, no erosioneilece se. fm as the leadisconcerned. i

owing' to its meros it provides an effective vcushion between the pouredmetal and the inner surface at the bottom of themold. AiterthoA moldandA ingot have cooled the ingo't may be remGYed leaving the lead in themold eithervas a. soiidiecl layer or in the molten condition. de-

pending upon-the temperature at which the inset irmoveq f l a cientamount of Altu'ittorn of lin the case ol a mold having a solid or closedbottom, in which case the walls taper downwardly, it is only necessaryto put into the'mold lead'to fox-m a layer of the desired depth.

In thecase of an open bottom mold closed by a bottom plate or plug, Iprefer to provide a lead seal outside of the lower part of the moldthrough which lead may be displaced by the weight of the molten steel.However, it'will be apparent that any other type of bottom closure y beemployed.

The various features of my invention are illustrated diaeratically, byway of example, inthe accomp drawing in which Fia. l ls a verticalsection of a closed bottomA ot mold embodying my invention, and

Fie. 2 is a similar section of an open bottom mold.

erring to the embodiment shown in Fia. l the invention is illustrated asapplied to an ingot ld ha a. bottom it and an upstanding or upriuht walllll which tapers downwardly so that thesolidied ingot may readily beremoved therefrom. The upper end of the mold may be provided with a hottop ring it. lnto the mold there is placed a quantity of metallic leadwhich melts and forms a pool il when the mold is heat above the meltingtemperature oi' 'the lead. It will be understood that il the lead is in'bottom ci i the mold the teeming steel must displace or erode the leadbefore it can reach the bottom of the mold and with a suilicient thickls@ oi lead, depending upon the dimensions of mold and the conditions ofteeming, the force the lead without actually contacting with the bottomoi the mold or contacting it with nicht? force that no substantialerosion m Fie. 2 the invention is illustrated as applied to an openbottom mold having a vertical wall il which tapers upwardly so that themold con be lifted upwardlyv from the solidled ingot. The the mold ormold cavity is closed by a bottom plate i5 'spanning the area of themold and extending below the lower edge of the mold wall and thenceupwardly as et i8 to f/orm a narrow channel or moet l1. A layer I l'ofmolten lead within the mold m may new or seep inw the channel Il withoutbeing lost. When molten i steel'is poured into the ingot its force orimpact will be taken up primarily by the layerv of lead I8 and when thelatter is entirely molten it might be displaced to a greater or lessextent beneath the wall of the ingot M and into the moat or channel l1before the lower part .of the'molten metal solidies in the mold. In anyevent, however, the layer of lead takes the impact of the molten steeland thus protects the bottom plate i5 from erosion. Erosion of the leadis of no consequence because it immediately takes the form of a liquidwhich does not alloy with or stick to the steel ingot. y

Through the above invention the surface o the mold on which the moltenmetal impinges is protected by a displaceable layer of metal which,having a melting point below that of the steel, assumes a liquid formagainst which erosion has not permanent effect.

inasmuch as the lead forms a smooth layer below the cast ingot and doesnot alloy with it. the ingot may readily be lifted from the bottom wallof the mold.

What I claim is:

1. A method of casting ingots of ferrous metal which comprises coveringthe bottom of an ingot mold cavity with lead and pouring molten ferrousmetal into said mold so that the stream of molten ferrous metal impingesdirectly on the lead.

2. A method of casting ingots of ferrous metal which comprises coveringthe bottom of an ingot mold cavity with a layer of molten lead andpouring molten ferrous metal into said mold so that the stream of moltenferrous metal lmpinges f directly on the lead.

3. A method of casting ingots ci ferrous metal which comprises placinglead in an empty ingot mold and pouring molten ferrous metal into saidmold so that the stream of molten ferrous metal impinges directly on thelead.

LEWIS B. LINDEMU'I'H.

